A gorgeous image from the Hubble Space Telescope shows a nearby star called R Aquarii that is the site of dramatic activity: violent eruptions of matter that is thrown out into the space around it. Informally dubbed as a “stellar volcano” for the way it is throwing out matter like lava spewing from deep underground, the star makes for a stunning image, but it also holds an unexpected surprise. The star is not one single object, but two.
Known as a symbiotic variable star, it consists of a red giant and a white dwarf that orbit each other in an ongoing dance. The red giant pulses, with its temperature and brightness changing over a 390-day period. This intersects with the 44-year orbital period of the white dwarf. When the white dwarf starts to close in on the red giant, it sucks off some of its gas via gravity and builds up the disk around it until this collapses and explodes, throwing off jets of material. Then the cycle begins again.
“This outburst ejects powerful jets seen as filaments shooting out from the binary system, forming loops and trails as the plasma emerges in streamers,” Hubble scientists explain. “The plasma is twisted by the force of the explosion and channeled upwards and outwards by strong magnetic fields. The outflow appears to bend back on itself into a spiral pattern. The filaments are glowing in visible light because they are energized by blistering radiation from the stellar duo that is R Aquarii. The nebula around the binary star is known as Cederblad 211, and may be the remnant of a past nova.”
You can see the pulses of the red giant in this video timeline of R Aquarii using data from Hubble collected between 2014 and 2023. It also shows the swirling material near the heart caused by previous jets.
This gives an idea of just how large the effects from this star are, as the material travels as much as 248 billion miles from the central core region — that’s 2,500 times the distance between Earth and the sun.
